docs: def heightmap_add_hill(
      hm: np.ndarray, x: float, y: float, radius: float, height: float
  ) -> None:
      """Add a hill (a half spheroid) at given position.
  
      If height == radius or -radius, the hill is a half-sphere.
  
      Args:
          hm (numpy.ndarray): A numpy.ndarray formatted for heightmap functions.
          x (float): The x position at the center of the new hill.
          y (float): The y position at the center of the new hill.
          radius (float): The size of the new hill.
          height (float): The height or depth of the new hill.
      """
      lib.TCOD_heightmap_add_hill(_heightmap_cdata(hm), x, y, radius, height)